Domestic Energy Demand Research Articles

A thorough analysis of renewable hydrogen projects development in Uzbekistan using MCDM methods

The energy supply system of Uzbekistan is not well positioned to meet the rapidly rising domestic energy demand of this country. Uzbekistan's current energy supply system is outdated and has very low diversity, as most of its energy comes from natural gas. In addition to producing immense amounts of greenhouse gas and environmental pollution, this situation is untenable considering the eventual depletion of fossil fuel reserves of this country. Uzbekistan's renewable energy sector is highly undeveloped, a situation that can be attributed to the lack of coherent policies for the advancement of renewable power and the low price of natural gas. However, this country has significant untapped renewable potentials, especially wind energy, that can perform a significant performance in the country's power generation plans. Also, producing hydrogen from renewable power can provide a good alternative to fossil fuels and help meet the needs of the Uzbek industrial sector, especially oil, gas, and petrochemical industries. In this study, the suitability of 17 regions in Uzbekistan for wind-powered hydrogen production was analyzed in terms of 16 sub-criteria in four categories of technical, economic, social, and environmental factors. To obtain robust results, the ranking was performed using a hybrid of BWM and EDAS, as well as WASPAS, ARAS, and WSM techniques. The weighting results exhibited the Levelized Cost of Electricity (LCOE), Levelized Cost of Hydrogen (LCOH), and Annual Energy Production (AEP) to be the most important sub-criteria for this evaluation. Nukus, Buhara, and Kungrad were introduced as the top three most appropriate locations for hydrogen development from wind plants. It was estimated that using 2000 kW turbines, a wind-powered hydrogen production plant built in the Nukus region can achieve an annual power output of 4432.7 MW and annual hydrogen output of 71.752 tons.

Modeling and analysis of a solar boosted biomass-driven combined cooling, heating and power plant for domestic applications

A solar-assisted biomass-based tri-generation system is suggested to provide domestic energy demands and studied from the perspectives of thermodynamics and sustainability. In the proposed combined system, gas and steam turbines are considered as the main power generation systems, while the chiller and an auxiliary heat exchanger exploit the thermal energy content of the effluent. A pressurized water circuit is also considered to harvest the waste heat from the employed steam cycle condenser and concentrated photovoltaic to feed the desired space heating. The main components of the integrated system are assessed exergetically to show the main exergy destructive units. The influence on the performance of the system of some decision parameters and summer/winter conditions as well is investigated. Results showed that the designed system is capable to feed 1241 kW space heating, 101.5 kW domestic hot water and 55.35 kW chilled water as space cooling, besides delivering 1MWe power. It is revealed that the pressure ratio of the air compressor leads to the system performance optimizing while the performance of the system has a linear relation with two variables of the gas turbine inlet temperature and cold end temperature difference within the air heater.

Theoretical and technical assessment of agroforestry residue potential for electricity generation in Brazil towards 2050

Bioeconomy, as a key strategic innovation pillar, supports energy transition and involves biomass resource assessment and its application. Biomass has an enormous potential to fulfil the domestic energy demand in Brazil. Hence, this study aims to quantify the theoretical, technical and techno-economic potential of agricultural and forestry residues to generate electricity via thermochemical processes in Brazil for the 2018–2050 timeframe. The analysis was carried out via an integrated approach, according to statistical reports and literature data. Conversion technologies for the estimation of technical potential consist of organic rankine cycle, combustion with conventional rankine cycle and gasification with an internal combustion engine. The results showed that Brazil’s theoretical potential is 7185.39 PJ and 16,708.12 PJ in 2018 and 2050. The technical potential in 2018 is 1795.16 PJ, generating 71,236.47 MWe, while the potential in 2050 is projected as 5771.49.4 PJ providing 229,027.31 MWe. The main restrictions are dispersed distribution of biomass over a large area, supply costs, and low efficiencies for energy conversion. Therefore, the techno-economic potential is around 19,704.01 MWe and 63,348.95 MWe for 2018 and 2050. The north region has the lowest electricity generation potential, while the southeast region takes a prominent position to generate electricity mainly from sugarcane residues. Levelized costs of electricity values varied from 10.532 to 15.507 US$/MWh for 2018 and from 7.320 to 13.002 US$/MWh for 2050, which highly influenced by the biomass price. The results of this study can support policy-making towards future planning on Brazilian bioenergy.

Political risk analysis of foreign direct investment into the energy sector of developing countries

Sustainable development is now a global pursuit, encompassing economic, social, and environmental dimensions. Energy figures as a primary driver of the economy and thus for achieving a sustainable future. However, chronic lack of access to reliable, clean energy supplies presents as a barrier to development. This is especially true of developing countries. Foreign direct investment is pivotal in meeting the demand. While studies have shown that foreign direct investment in energy is significantly affected by political risk, the impacts of specific political risk factors across different country environments remain unrevealed. This study seeks to address this gap by identifying the impacts of specific political risk factors on foreign energy investment, and by investigating how these impacts are then moderated by further determinants. Panel data analysis is employed to explore the significant political risk factors impacting foreign energy investment in 74 developing countries, using data from 2008 to 2017. Analysis reveals that risk of investment profile, law and order, religious tensions and corruption result in significant political risk affecting foreign energy investment. However, these results are moderated across countries by further factors such as gross domestic product, economic freedom and energy demand within host countries. Clustering techniques reveal seven country groups sharing common moderating factors, significant to foreign energy investment. This insight reveals that lessons from one within-cluster nation will offer relevant lessons on energy investment across to others within the same cluster. Furthermore, based on the impact divergence in different country groups, practical suggestions government and foreign investors are also proposed.

Enhancement in Free Cooling Potential through Evaporative Cooling Integrated with PCM Based Storage System: Experimental Design and Response Surface Approach

PCM-based thermal energy storage in conjunction with an electric air source is offered as a potential tool to support domestic energy demand reduction while at the same time minimizing supply challenges for the electricity utilities. This study is to advance the use of hybrid ventilation concepts in building design by assessment of PCM storage unit with an operation of the evaporative ventilation system. RSM CCD methods was employed to evaluate and optimize the individual/interactive effect of parameters on the cooling efficiency of the proposed system. Optimization results indicate that maximum efficiency can be achieved when inlet air temperature and velocity of 28 oC and 1.2 m/s when PCM coils number was set to 28, respectively. This research compared the effectiveness of the passive and free cooling application of PCM when applied to a duplex brick veneer building in Melbourne. It was observed that during the studied period, the free cooling application method is more effective than the passive application method in reducing the peak zone temperature.

Building form and energy efficiency in tropical climates: A case study of Penang, Malaysia

Abstract Malaysia is a nation that has undergone a massive development based on its abundance of fuel supply. The imbalance ratio between gross domestic products and energy demand clearly indicates the need to promote energy-efficiency strategies in the country. This study investigates the relationship between building shape and energy consumption by considering the control of excessive solar radiation in a tropical climate. In the first step, four basic plan geometries, namely, square, rectangle, triangle and circle shapes, are studied to determine the optimal building shape in terms of energy consumption in Penang, Malaysia. Results of simulation analysis using DesignBuilder software (Version 5.4.0) reveal that the circle is the most suitable form in terms of energy performance. In the second step, all buildings with extended shapes based on the optimal shape obtained from the first step are simulated under the same condition to analyse the thermal behaviour of different building forms. Amongst four alternative extended cases, Case 3 with 90 cm depth and without vertical offset from the top of the window has superior energy performance and sufficient natural daylight. This study contributes to enhance energy efficiency of new buildings by incorporating design strategies in the design process.

A framework for the study of householders’ engagement with low-carbon energy demand practices in dwellings with grid-connected photovoltaic energy systems

Introduction: This paper introduces a framework to assess householders’ interaction with grid-connected photovoltaic (PV) systems in domestic buildings, in an attempt to research the question To what extent the engagement of occupants in energy demand management practices is relevant for the operational CO 2 emissions reductions in dwellings with on-grid PV systems? The focus is placed on identifying the engagement with low-carbon operation practices and its relevance for final CO2 emissions from electricity consumption. Specifically, PV electricity Self-consumption and energy conservation practices are studied. To this extent, the research builds on i) the energy services approach and ii) the social practices approach to domestic energy demand. The context of owner-occupied houses which have been retrofitted with PV installations in South Wales, UK is taken as an example. Methods: After a brief conceptual review on domestic energy demand, a mixed-methods framework for the study of householders’ engagement with low-carbon energy demand practices is presented, comprising three key aspects: a) the conditions for the practices to occur, b) frequency with which householders enact the practices, and c) the estimation of final operational CO2 emissions performance. Results: As part of ongoing research work, a framework to study households’ engagement with low-carbon energy demand practices in buildings with grid-connected PV technology is proposed; focusing on the obtention of a socio-technical lecture to complement other sources of in-use assessment data. Conclusions: Besides single case-studies, the framework has potential applications in recognising and grouping households’ engagement profiles. In this way, it is suggested that the framework might facilitate the analysis when extensive assessments are needed; such as in public policy evaluation or demand response studies. Grant Support: This work is funded by CONICYT PFCHA/DOCTORADO BECAS CHILE/2018 - 72180375.

Japan’s Balanced Strategy to Face China’s Threat in South China Sea Dispute

This paper aims to analyze Japan’s foreign policy related to the dispute in the South China Sea (SCS). Even though Japan has no sovereignty claims, it has considerable interests in the SCS region. Japan, which is poor in natural resources, depends on energy imports, most of which are shipped through SCS. As an advanced industrial state, Japan must continue to meet domestic energy demand. However, the SCS area has a potential conflict due to Chinese assertive behavior as the main factor that could threaten Japanese interests. The author use qualitative method with relevant literature studies and official government documentation to conduct a descriptive analysis of the research findings. The results of the study indicate that Japan is implementing a balanced strategy to deal with the potential threat of China. Balancing against threats is conducted in internal ways, e.g. internal reinforcement, and external ways, e.g. forming and strengthening cooperation with other countries outside the United States (US). Since Japan's limitations in military aspect hindered their internal reinforcement, this study emphasizes Japan's external balance strategy. The increasingly dubious US commitment in the Asia Pacific has made Japan strengthen defense cooperation with Southeast Asian countries such as Indonesia, the Philippines and Vietnam. The three countries have interest in SCS and provide access that conforms to Japanese interests.

Domestic sector energy demand and prediction models for Punjab Pakistan

The domestic sector consumes ~48% of Pakistan's total energy demand, including biofuels. Pakistan is an emerging economy with 210 million people and growing domestic energy demand, facing economic, geographic, geopolitical, and climate change challenges. This paper presents novel insights into the Punjab, Pakistan domestic sector energy demand, which accounts for over 52% of the Pakistan population, along with energy prediction models derived from a statistically significant 4597 responses obtained from a physical questionnaire survey conducted in 2017-18, which aimed at ascertaining the main domestic energy demand drivers. These models will support future government and energy industry policy in this area, especially the transition to a low carbon economy. Currently, 67% of Pakistan's energy demand is met with non-renewable resources. Analysis of the survey data reveals the key drivers of electrical energy demand per household are the number of appliances, number of lights, and the number of conditioned rooms. In the per capita models, the key drivers are the overall power rating of the appliances, particularly the power rating of the air conditioners for cooling. For annual gas use, weak correlations per household and capita were found only for the floor area. The average annual electricity and gas usages per household are 2401 kWh/a and 5245 kWh/a respectively, and per capita are 391 kWh/a and 770 kWh/a. For electricity, the occupancy, floor area, conditioned rooms, appliances, lights and power rating have predictive power. For gas, only floor area is predictive.

A Review of Power Electronics Applications for Wind Energy Systems in Microgrids

Wind energy conversion systems continue to show promises as energy source of the future. To champion the supply for future industrial and domestic energy demand, it is imperative to improve on their reliability, energy extraction efficiency and security as these factors would enormously affect their viability and deployment. This paper presents an overview of the applications of power electronics to speed control of generators in wind energy conversion systems. Wind energy conversion system, the basis on which they are classified and their various components are concisely reviewed. Further, an up-to-date highlight of wind turbines speed control schemes is presented with focus on the roles of power electronics in these schemes. Concluding, necessary technological and economic development to aid applications of power electronics devices in emerging wind energy systems and their significance to the microgrid is understudied.

Design, realization, and tests of a portable solar box cooker coupled with an erythritol-based PCM thermal energy storage

Solar radiation is a variable energy source and the mismatch between the availability of such source and the domestic energy demand is a paramount challenge to deal with. For this reason, in this work a 4.08 concentration ratio portable solar box cooker coupled with a thermal energy storage (TES) based on a phase change material (PCM) was characterized through outdoor experimental tests. The TES is a double-wall stainless steel vessel, with the annular volume filled with 2.5 kg of erythritol. The portable solar box cooker was tested under 4 different experimental conditions: without load, with water, with silicone oil, and with silicone oil inserted in the erythritol-based TES. The load tests were divided into a heating and a cooling phase, in order to evaluate the cooker performance in absence of solar radiation. Results showed that equipping the portable solar box cooker with the erythritol-based TES allowed to extend the average load cooling time, in the range 125–100 °C, of around 351.16%.

Regression analysis for energy demand projection: An application to TIMES-Basilicata and TIMES-Italy energy models

A reliable energy supply is fundamental to ensure energy security and support the mitigation of climate change by promoting the use of renewable sources and reducing carbon emissions. Energy system analysis provides a sound methodology to assess energy needs, allowing to investigate the energy system behavior and to individuate the optimal energy-technology configurations for the achievement of strategic energy and environmental policy targets. In this framework, the estimation of future trends of exogenous variables such as energy demand has a fundamental importance to obtain reliable and effective solutions, contributing remarkably to the accuracy of models’ input data. This study illustrates an application of regression analysis to predict energy demand trends in end use sectors. The proposed procedure is applied to characterize statistically the relationships between population and gross domestic product (independent variables) and energy demands of Residential, Transport and Commercial in order to determine the energy demand trends over a long-term horizon. The effectiveness of linear and nonlinear regression models for energy demand forecasting has been validated by classical statistical tests. Energy demand projections have been tested as input data of the bottom-up TIMES model in two applications (the TIMES-Basilicata and TIMES-Italy models) confirming the validity of the forecasting approach.

Estimating Ultimate Recoveries of Unconventional Reservoirs: Knowledge Gained from the Developments Worldwide and Egyptian Challenges

Supertight oil and gas reservoirs have always been considered uneconomical. Their high stimulation costs, forecasting the future production and estimating the ultimate recovery (EUR), have long been problematic. They should be constantly updated during the lifetime of a reservoir, besides; their accuracy depends on the amount of available data and the adopted method. However, after the enormous production in North America, exploring and developing unconventional hydrocarbon resources are gaining more interest worldwide. Nowadays, the Egyptian government is targeting tight layers/zones, in the western desert, to increase the high domestic energy demand and hence, increase the annual production of the conventional – high permeability – reservoirs. Several zones within Khatatba source rock in the Shoushan basin as well as in the Abu Gharadig basin are now being studied and evaluated to maximize their productivity and identify the optimal technology for future developments. In the present work, various approaches, used in predicting the performance of unconventional reservoirs, are investigated and compared through their forecasting future production and their estimated ultimate recovery (EUR). Traditional Arps’ decline, for low permeability reservoirs, over-forecasts reserves. Power-law exponential decline (PLED), stretched-exponential decline (SEPD), logistic-growth model (LGM), and Duong’s method have been used to represent the rate/time production data for the standard well completion in a multiple-fractured horizontal well in a shale play. These methods provide different forecasts as they are based on different equation forms. Unfortunately, previously mentioned methods are not satisfactorily adequate to forecast production for all unconventional reservoirs. The rate transient analytical (RTA) models require certain modifications of the reservoir and fracture parameters to provide optimistic EURs when compared to the numerical simulation. In this research, based on the production forecast and EUR prediction, different models for forecasting unconventional well data have been reviewed and compared. Production data has been used to validate the accuracy of the models, show the similarity of reserves estimation, and reveal the relationship to the reservoir theory. This work might help the Egyptian operating companies to better understand the production dynamics of unconventional reservoirs and suggest a more reliable model EUR’s estimation.

Sizing of district heating systems based on smart meter data: Quantifying the aggregated domestic energy demand and demand diversity in the UK

The sizing of district energy systems involves a trade-off between reliability and continuity of service, and avoidance of capital and running costs associated with oversizing. Finding the most appropriate sizing requires a thorough understanding of energy demand. However, empirical data necessary to support such an understanding is scarce, and district energy systems are typically oversized. This study uses smart meter data from the largest field trial to analyse residential energy consumption in the UK. It presents graphically the seasonal and daily variations in energy consumption patterns, the weather dependence of energy loads, and peak hourly demand during particularly cold weather conditions. It also explores the diversity effect in residential energy consumption and computes the after diversity maximum demand at different levels of aggregations. Results show that, peak hourly gas consumption was nearly seven times higher than electricity consumption during the cold spells, while diversity reduced gas and electricity maximum demand per dwelling up to 33% and 47%, respectively. This empirical quantitative analysis of energy demand and diversity can support improved design and operation of district energy, and in particular, enable reduced capital and running costs, and an improved understanding of economies of scale for district heating networks.

Implications of declining household sizes and expectations of home comfort for domestic energy demand

Techno-economic approaches largely avoid delineating necessary energy uses or questioning how excessive lifestyle expectations may curtail attempts to achieve ambitious climate change targets. In this Perspective, I present data suggesting a general trend of increasing domestic floor area per capita globally and argue that this ought to be a key focus in future energy research, considering that house size is the largest determinant of domestic energy consumption. Particular attention should be directed at the confluence of factors that influence floor area per capita and questions of lifestyle expectations, energy sufficiency and invisible energy policies that have enabled the rise in floor area per capita both deliberately and inadvertently. Overall, this elucidates why energy research must consider lifestyle expectations and demographic trends that are generally seen as outside the remit of energy policy. This Perspective suggests that the combined influence of trends toward increasing house size and decreasing household size have important implications for energy consumption per capita. This points to new avenues for research and policy related to lifestyle expectations and housing development.

Heating systems through the lens of the boiler: Detailed case studies to inform current and future heating system design

Boilers in hydronic heating systems are the norm in the UK. Through case study analysis, covering four houses with gas central heating systems for over one year and utilising novel monitoring of the on-board diagnostic data of the boilers, performance issues were identified in this mature technology. ON/OFF cycling behaviour and oversizing were prevalent with boilers consistently unable to modulate low enough to match the building space heating demand. Cycling behaviour resulted, known to be detrimental to efficiency, with the majority of boiler operations lasting less than 10 min. Targeted case study analysis of incumbent technologies, such as boilers, utilising the latest in data collection techniques and connected appliances provides a cost effective insight to broader issues. Implications for domestic energy demand range from incremental improvements in boiler system efficiency by addressing cycling to the updating of building energy assessment models (e.g. Standard Assessment Procedure) to reflect and reward the benefits of good installation practices. An improved understanding of boiler operation may support improved product design and installation practices and are beneficial to the next generation of domestic heat, such as heat pumps. By undertaking continued in situ analysis of the incumbent technology, a more thorough foundation for the future can be ascertained. Fundamental issues of oversizing and detrimental cycling behaviour are persisting in the industry. Practical steps can be taken immediately to avoid oversizing of boilers. Building an awareness of performance penalties associated with poorly planned heating installations will have added benefit for more dynamically sensitive technologies in the future, such as heat pumps.

Home Comfort and “Peak Household”: Implications for Energy Demand

ABSTRACT This paper draws on a study of Scottish householders living in “zero-carbon” homes. It explores how broader understandings of home comfort may explain changes that result in home life becoming increasingly energy demanding, despite householders’ intentions to save or decarbonize energy. The paper argues that domestic energy research must engage with the dreams, aspirations, and images of home that ultimately drive consumption and impact investment in housing and home energy improvements. This is done by examining the interrelationship between energy retrofitting and installing microgeneration technologies alongside discussing meanings of home comfort and visions of ideal homes with householders. The study argues that an important aspect of home improvements is due to accommodating the “needs” of the peak household. The paper concludes by discussing how a wider range of people and interventions could be pursued to reduce domestic energy demand such as promoting downsizing or working with home or lifestyle companies.

Balancing intersectoral demands in basin-scale planning: The case of Nepal's western river basins

Abstract Basin-wide planning requires tools and strategies that allow comparison of alternative pathways and priorities at relevant spatial and temporal scales. In this paper, we apply a hydroeconomic model–the Western Nepal Energy Water Model–that better accounts for feedbacks between water and energy markets, to optimize water allocations across energy, agriculture, municipal, and environmental sectors. The model maximizes total economic benefits, accounting for trade-offs both within and across sectors. In Western Nepal, we find that surface water availability is generally sufficient to meet existing and growing demands in energy and agricultural sectors; however, expansion of water storage and irrigation infrastructure may limit environmental flows below levels needed to maintain the full integrity of important aquatic ecosystems. We also find substantial trade-offs between irrigation in Nepal and satisfaction of the institutional requirements implied by international water-use agreements with the downstream riparian India. Similar trade-offs do not exist with hydropower, however. Model results and allocations are sensitive to future domestic and international energy demands and valuations.

Joint development in the South China sea: China’s incentives and policy choices

ABSTRACTSince 2017, China has actively proposed a number of joint development schemes in the South China Sea (SCS), namely with the Philippines and Vietnam. Both economic and strategic incentives lie behind China’s development of these schemes. China’s economic incentives include its domestic demand for energy, “21st Century Maritime Silk Road” construction, Hainan the pilot free trade zone construction, construction of a common market and the future economic integration among the SCS coastal States. China’s strategic incentives include achieving its goal of becoming a leading maritime power, playing its constructive role in maintaining a peaceful and stable SCS, developing good relations with other coastal States, and reducing the intensity of China-U.S. competition in the SCS. China’s policy choices on the SCS joint development are as follows: first, to promote good faith in the SCS; second, to limit unilateral activities in disputed areas; third, to focus on less sensitive areas of the SCS; fourth, to reach joint development arrangements by establishing relevant working mechanism; fifth, to begin the process in areas where there are only two claimants; sixth, to define sea areas for the joint development by seeking consensus; seventh, to discuss the feasibility of setting up a Spratly Resource Management Authority (SRMA) with supranational character.

Can fuel cell micro-CHP justify the hydrogen gas grid? Operating experience from a UK domestic retrofit

Fuel cell based micro combined heat and power (micro CHP) has been the subject of numerous simulation studies. We report on actual practical performance of a proton exchange membrane fuel cell (PEMFC) micro CHP in a UK dwelling over the 2017–18 heating season and compare its performance with a Stirling engine micro CHP which it replaced. Results show that the PEMFC micro CHP achieves a much higher annual electricity output over a year, with household self-consumption and operating economics dependent on electric vehicle charging. Empirical models derived from this operating experience show that the value of this technology is less sensitive to building parameters, occupancy, and climate change when compared to engine-based micro CHP. We consider the potential role of this technology in the decarbonisation of heat, and highlight the benefit of reliable electricity generation injected into low voltage distribution to mitigate winter demand peaks from heat pumps. A comparative analysis of the primary energy efficiency of different methods of meeting domestic energy demand using natural gas with carbon capture shows that a mixed solution to decarbonisation of heat, combining heat pumps, PEMFC micro CHP, and hydrogen boilers, should not degrade energy efficiency substantially by comparison with an all-electric solution and could be more acceptable to consumers.